Allergen Extract Compatibility (Esch/Greer)

Green - Stable, retain near-complete levels of target allergen activities (>70% recoveries compared with control samples) under refrigerated storage conditions (2-8 C, 36-4 6F) at low (10%) glycerin concentration
Yellow - Risky, noticeable degradation of target allergens (50-70% recoveries vs controls) during storage at 2-8 C, which was prevented or improved substantially at higher (25%) glycerin levels
Red - Unstable, target allergen potencies not protected or stabilized under most conditions, and often reduced significantly (<50% recoveries relative to controls) within 3 months when stored continuously at 2-8 C

Practice Parameter 2011

Separation of extracts with high proteolytic enzyme activities from other extracts is recommended.
It might be necessary to prepare 2 or more vials to provide allergen immunotherapy containing an optimal dose of each component while avoiding allergen extract combinations that might result in degradation of some or all of the components.
Consider keeping extracts that have high proteolytic enzyme activities, such as fungi and cockroach extracts, separate from those extracts susceptible to their action, such as pollen.
It is not recommended to mix venoms together (eg, wasps or honeybee with yellow jacket), even though yellow jacket and hornet venom are available premixed as a mixed-vespid extract.

The safest policy is to not mix pollen, animal dander, or house dust mite extracts with those of fungi or cockroach and to mix fungal and cockroach extracts but only in a solution containing 50% glycerin.

Usually described as compatible (see above), however a recent Greer study demonstrated significant loss of allergen in Alternaria-insect (cockroach, fire ant) combinations and German cockroach-fungal combinations, therefore separation of these allergens into different treatment vials may be required to produce stable mixtures